South Africa

South Africa
Click on pictures for larger view, contact me at williams4x4@gmail.com

17 February 2010

Fuse box info and relays, new update with latest easy mod to prevent damage

Update on the below proposed update.... its been slow but its coming to this blog soon.

UPDATE to follow on how to remove and supply the 3 BeCM wires that attach to the bottom of the fuse box with its own dedicated power supply, these fuse box's are over loaded and is a design fault.
Mod will detail a separate 3 link fuse connection, its very possible that this mod will solve a few current supply issues like odd ABS, dash dials odd behavior etc 

The handbook lists all the fuses but nothing on the relays


RL means relay
Be advised that you can use basic relays that are available from auto electrical suppliers or spare shops BUT a quality brand like Siemens, Bosch is highly recommended, speak to a auto electrician if in doubt. 

1   RL18 AC control relay
2   RL13 AC condenser fan 1

3   RL11 Head lamp wash wipe

4   RL8 Front wiper interval relay

5   RL1 Front wiper control relay

6   RL19 Engine main control relay

7   RL14 AC condenser fan 2

8   RL2 ABS power relay

9   RL 20 EAS compressor relay

10 RL15 Ignition coils, MAF sensor  **Important relay**

11 RL4 Right heated front screen

12 RL16 Starter relay

13 RL5 Left heated front screen

14 RL17 ABS pump **Don't mess with this one, buy genuine if in doubt - Do not modify a  standard relay to fit as contacts will fuse and will burn out your ABS pump**

15 RL6 Right blower motor

16 RL12 Fuel pump relay

17 RL7 Left blower motor

18 RL9 Hooter relay

Apart from the ABS pump relay being black DO NOT install other black relays within the fuse box
The yellow and green relays are different by pin design compared to relays bought over the counter from spares shops

The ABS relay is a special double contact design due to the start up current of 70 amps going through it, you must replace this relay with the correct one from Land Rover as these too are not available elsewhere


Maxi Fuses supply the BeCM with power

3 cables secured onto the underside of fuse box go to the BeCM

The slot “Not used” is normally populated with a spare relay.


REPAIRING THE FUSE BOX:

It is possible to carry out repairs to the fuse box but a simple fault like a bad relay can lead you to believe it is the fuse box, a relay can still click and show ok when testing but is another situation when a load goes through its internal contacts

None the less a fuse box can go wrong and is repairable, I've done a few with good results even though they are a pain to do
Below are a few pictures just so you can see how complex they are, its a well built unit using lots of thick copper




The stripping process is easy as to is the splitting the two halves, its the reassembling that takes most of the time with re soldering in new connection joiners, takes around 5 hours non stop.





NEW update from here
A few more pics to be added very shortly on how to repair the above burnt main battery cable connection with the use of a starter motor solenoid copper bolt, this allows for good soldering and wide spread support of current flow.


In the above picture on the left is the original power post in the fuse box, to the left is the starter motor solenoid copper bolt that is used in the repairs of the fuse box.




The above fuse box would in most cases been deemed throw away, this one was so bad I decided to give it a try and the results were positive.



Above pic is to show how the lug needs to be bent to allow for the plastic cover to fit, minor enlargement of the hole is required.









To add the new mod two holes barely larger than the solid core copper cable being used needs to be drilled through the PC board and soldered (As illustrated above circled in red)
The cabling used is normal house electrical sections, preferably the thicker type used for geyser power supply as its rated a higher current resulting in it being thicker and ideal.
This add on can be done without splitting the board sections and a must do even on a brand new fuse box 

Its the way these fuse/relay boxes should of been manufactured in the first place......



Interesting that something so basic to make up can have a major impact on current spread, we now carry out this mod to all fuse boxes we repair, better than new and I'm surprised the manufacturers don't do the same...oh wait, if they did they would not be selling fuse boxes

Relays...

New update added in May 2015, engine power

Pics on ABS pump relay and other relays within the fuse box opened for all to see regarding why cleaning up the contacts can have a positive effect


P38 ABS relay, this one fused and caused the ABS pump to burn out

Standard relay, please do not modify one of these for use as a ABS relay, it will fuse together and burn out the ABS pump - Guaranteed and I've seen it happen, do not simply let anyone replace or service the braking system on the P38 if they don't specialize on these vehicles.
Apart from WILLIAMS 4X4 I know of nobody else here in South Africa 

Standard relays can be cleaned up nicely, use fine 1000 grit sand paper, good for another life time.